Carton



July 23, 1963 A. w. HAGAN 3,098,599

INVENTOR. ALERT W. HAGA/v aff/Wm sb/OMM/ July 23, 1963 A. w. HAGAN 3,098,599

CARTON Filed Aug. 24, 1961 '5 sheets-sheet 2 INVENTOR.

ALBERT W. HAGA/v JMa/f/ne/z/ 91 A TMR/v5 mi July 23, 1963 A. w. HAGAN 3,098,599

CARTON Filed Aug. 24, 1961 3 Sheets-Sheet 3 INVENTOR ,4L @ERT W. HAGA/v ATTORNEYS United States PatentO 3,098,599 CARTON `Albert W. Hagan, Stratford, Conn., assiguor to Roy S.

`Sanford & Company, Oxford, Conn., a partnership Filed Aug. 24, 1961, Ser. No.'133,705

6 Claims., (Cl. 229-37) This invention relates to cartons of paperboard, fibreboard and other sheet materials suitable for the formation of `cartons having foldable end iiaps,` and particularly to a novel sift-proof construction for a carton of the above type.

' 'One'of the objects of the present invention is to provide a novel paperboard carton blank which is readily adapted for quick and eiiicient sealing `at the ends thereoffthe construction being such that complete sealing of all pinholes'and cracks is achieved, thus providing a con- -tainer having end portions Iwhich are completely Isiftproof when the carton is utilized for powdered materials such as ilour, for example.

Another objectief the invention is the provision of la carton construction `so constituted as to eliminate the need i-for inner' bags `or overwraps commonly utilized for the #purpose of preventing the sifting .of the powdered contents.

-Aiurther object of the invention is to provide a sift- Aproof carton'of polygonal cross section for-med from la singlepiece of low cost material `such `as paperboard.y

Still another object yof the invention is to provide a one piece carton blank so constituted as to permit folding in such 'a manner as to effect efficient and positive sealing of the Iend tiaps under relatively low pressure.

In the manufacture of paperboard or fibreboard 'cartons of this general type, it is not too diiiicult to properly seal one endof the container, since when the first end is sealed, lthe end iiaps can be held together under high 4pressure, a mandrel tbeing inserted in the container to vsupport the-flaps on one side, and a pressure plate being Yforced against the flaps on the outside in order to properly seal `the flaps. Difficulty is experienced, however, in sealing the other end of the container after it has been illed, `and 'it Ais a fur-ther and important `object of the invention to yovercome this diiiiculty, and to provide a construction wherein the endof the carton which is sealed after iilling fof the cartoncan be madesiit-proof with very little pres- .'sure being applied to the folded end aps which close i the end of the carton.

*l A still further object of the invention is to provide Ia `new and novel corner construction for a carton.

Yet another object of the invention is to provide a corner 'construction `for a paperboard carton which will stand rough handling Without causing the corners of the carton to leak.

Stillwanother object of the invention is to provide a car- -ton fblank* for a` sift-proof carton, so constituted as to .permit folding of the carton and glueing ofV the side seam -to provide a Yhat: shell which can 'be shipped from the carton manufacturing plant and set up at any desired point to form a completed carton.

These and other objects and novel features of the in- ,vention will appear more #fully hereinafter from the following detailed description when taken in connection with the iaccompanying drawings, wherein one embodi- `ment of the invention is illustrated.

It is to be expressly understood, however, that the drawings are utilized for lpurposes. of illustration only, and are not to be taken as a delinition of the limits of the invention, reference being hadfor `this purpose to the appended claims.

Inthe drawings, wherein similar reference characters referto similar parts throughout the severallviews:

PIG. l is a plan'view of a blank adapted to be `formed into a carton'of the above type;

3,098,599 Patented July 23, 1 963 ICC `V2 FIG. 2 is a perspective view of acarton ltubeformed from the-blank of FIG. l;

FIG. 3 is a` perspective-view of a` completed-carton formed from the blank offFIG. l;

FIG. 4 is an enlarged fragmentary perspective View of a carton corner-during `one stage of the end sealin-g operation;

FIG. 5 4is a` sectionalview of-the corner shownin FIG. 4; FIG. 6 is la fragmentary perspective view of the corner shown inv FIG. 4 at the completion of the end sealing A operation;

`this connection, it should @be noted that the corner of a conventional carton of the type utilized for the packaging of ilour, cake mixes or the like, is a very rigid structure, and that iny the event the carton is dropped on the oor and hits on one of the-rigid corners, the carton isgen- ^erally damaged `to such an extent as to cause serious sifting of the contents. In the event an overwrap is used, this is Igenerally of thin paper and easily ruptures `at the corners, and sin-ce the carton-itself is not sift-proof at the corner; leakage* occurs. `It is well known that such cartons receive rather rough handling in chain grocery-stores and -the like,xand consequently the loss dueto damaged f cartons is quite high.

The carton of the present invention has a corner construction Awhich overcomes these difculties,` since the corner is not rigid in the sense that the corners of a vconventional car-ton are rigid, and while crushing of the corner due to `dropping the carton may change the appear- Vance of the comer-bydistorting the paperboard, it does not cause leakage or sifting of the contents at the corner. Cartons of this construction have been dropped repeatedly from heights of two or .three feet without causing sifting .of-.theicontentsfthe contents utilized in these tests being very nely ground flour. A Explaining the matter in another way, it is pointed out that the rigid corner of the conventional. carton 'buckles when Idropped lon thefloor,

thus rupturing the paperboard, A-while the' carton of the present. invention may be Iconsideredzto have the corners already( buckled'slightly, sothat further displacement of the paperboard can occur without rupture.

Carton constructions have previously been proposed wherein sift-proof corners" could be formed,l but some of these constructions have the disadvantage that they could not he formed into flat shells 1having thefsde seams glued, and consequently could not be shiped at to the-packaging plant to beset up in machines .at that plant.' The carton 60 of the present invention is soconstituted' that` the carton -side seamglueing machinesandthereafter shipped `flat to the packaging plant.

blank may be folded andrsideseam'ed on conventional Referring more particularly to FIG. 1,-the, present invention is illustratedtherein as-including :ar container blank; sh-own lfor convenience in `description in ya vertical position, and having main-side wall panels 5, 6, 7 and-8 and al glue hap-panel 9 adjoining the right side of the `panel 8. At the upper end of the blankft-here are provide-d lcorresponding fold-able endflaps l10,` 11, 12, 13 and `14, the bottom end ofthe blank being provided with corresponding foldable endaps`15, 16, 17, 18 and 19. The

. I?,` the flaps :111 and 413 and i116 and 118 are major flaps, the length of the latter being equal to the width of side wall panels 5 and 7. The upper foldable end liaps are sepa- `rated as shown by cut lines 20,' 21, 22 and 23, while the lower foldable end iiaps are separated by cut lines 24, 25, 26 Iand 27. In order to permit folding of the blank to provide a shell or :a carton tube, the junctions of the side VWall panels are deined by score lines 28, 29, 30 and 31.

The junctions of the side wall panels with t-he upper foldable end iiaps are defined by horizontal score lines 32, 33, 34, 35 and 36, and at the lower end of the blank by horizontal score lines 37, 38, 39, 40 and 41, Although the score lines between the side wall panels are referred to as vertical lines, and .the score lines at the junction of the sidewall panels and foldable end flaps are referred to as horizontal score lines, it is to be understood that these terms are used for convenience and clarity in description only, and that the blank may be otherwise oriented.

As shown in the drawing, each pair of adjoining verti- Vcal panels and a pair of corresponding foldalble end liaps are connected by a common integral quadrilateral panel of substantially diamond shape, the panels at the upper end of the blank being identified by the numerals 42, 43, 44 and '45, and at the lower end of the blank by the numerals 46, `47, 48 and 49. The panels just referred -to at the upper end of the blank, for example, are preferably of the same sine and shape, and it will be noted that the lower sides of the panels are formed by diverging score lines S and 51 which diverge from a common point on the vertical score lines 28, 29, 30 and 31 below the center line of the horizontal score lines 32, 3-3, 34, 35 and 36 and intersect the horizontal score lines 32 and 33, 33 and 34, 34 and 3S and 35 and 36 on either side of the center line of the score lines 28, 29, 30 and 31 respectively. The other two sides of the panels are formed by converging score lines 52 and 53 on foldable end llaps 10 and 1.1, 11 and 1-2, L2 and 13, and 113 and 14 respectively, these being lines which extend angularly upward from the junctions of the score lines 50 and 51 with the horizontal score lines to the ends of cut lines 20, 21, 22 and 23. The quadrilateral panels 46, 47, 48 and 49 at the lower end ofthe blank are defined in the same manner. The score lines may for-n1 equalateral diamond shaped panels, or the panels may be shaped as shown in FIG. 1, but in any case, the included angle between the score lines 50 and 51 should preferably be an obtuse angle, as should also the included angle between the score lines 52 and 53, and in the preferred form, the included angle between the score lines 50 and 51 should be equal to or greater than the included angle between the score lines 52 and 53.

In one preferred .form of the invention, cartons were made from paperboard having a thickness of .0201 inch, and in this instance, the score lines 50 and 51 were at an angle of approximately 10 to the horizontal score lines, and the score lines 52 and 53 were at an angle of -181/2 to the horizontal score lines, the horizon-tal distance between the apices o-f the panels being approximately .75 inch. Other angles and panel sizes can be utilized, howeverthis depending to a considerable extent on the thickness and the type of paperboard utilized. In general, however, the arrangement shown is very satisfactory for ordinary cartons of relatively small size using conventional paperboard material.

When the car-ton blank is folded to for-m a flat shell, it will be understood that the panel 8 will be folded about the vertical score line 30, and the panel will be folded about the vertical score line 28 with the inner surface at the edge portion of the panel 5 and at the edge portions o-f the end liaps 10 and 15 overlapping the ou-ter surfaces of the glue flap panel 9 and the corresponding end iiaps 14 and 19, and being .adhesively secured thereto.

4 The surface shown in FIG. l is the inner surface of the carton when folded.

In order that the end -iiaps may be subsequently folded satisfactorily to form a carton following the opening of the shell into tubular form, triangular notches 54 and 5'5 are cut in the left edge Iof the blank. The notch 54 is defined on the lower leg of the triangle by a cut line 55a extending from a point on the horizontal score line 32 to the left edge of the blank at the same angle to that score line as that made by the score lines 50 and 5-1, while the upper edge of the triangular notch is defined by cut line 5:6 extending from the same point on the score line 32 to the edge of the flap 10 at the same angle as the score lines 5-2 yand 53, the cut lines 55a and 516 respectively having substantially the same lengths as said score lines. Notch 5-5 is defined in the same manner. Consequently, when the surface of the left end of the blank is adhesively secured to the surface of the glue iiap 9 and the flaps 114 and 19 as Iabove described, the edges of the notch 54 conform substantially to score lines S1 and 53 of the quadrilateral panel 45, while the left end ofthe score line 32 registers wit-l1 the horizontal score line 36 separating the glue flap panel 9 from the end ap 14. Thus, when the blank is later folded to close the end flaps, it is not necessary to fold a double thickness of paperboard in the region of the right portion of the quadrilateral panel 45'. In the event the angularity of the score lines defining the quadrilateral panels .is changed, the cut lines 55a and 56 of the notch 54 are changed accordingly. It will be understood that the same construction may be utilized at the lower end of the blank as indicated in the drawing. Consequently, the same reference numerals are applied to the score lines at the lower end of the blank which form the quadrilatei'al panels.

As shown in the drawing, the vertical score lines 28, 29, 30 .and 31 do not extend through the quadrilateral panels, and in like manner the horizontal score lines 32, 33, 34, 3S and 36 are not extended through these panels. Although the above score lines' can be extended through the quadrilateral panels if desired, it has been found that this does not materially improve the structure, and also it may be Idifficult for the carton plant to impress these score lines on the blank. Consequently, the preferred form of the invention is as shown in FIG. 1 of the drawings insofar as these score lines are concerned.

Referring to FIG. 2, it will be noted that the blank has been folded to form a carton tube. -As shown in the drawing, the edges 55a and S6 of the notch 5-4 substantially coincide with the score lines 51 and 53 of the panel 45. Due to the fact that the vertical height of the quadrilateral panels from their lower apices to their upper `apices is relatively short, it will be understood that the blank can be folded as shown to form a flat shell without damage to the unscored paperboard along lines extending vertically through the centers of the quadrilateral panels.

Following the formation of the carton tube as heretofore described, the Ifoldalble end flaps may be folded in overlapping relationship and adhesively secured together in the customary manner. Although the end liaps 10 and 12, together with the ilap 14 secured to flap 10, are preferably folded in first, with the flaps y13 and 11 thereafter folded in overlapping relationship in the order named, it will be understood that this is a matter of choice, and does not affect the eiciency of the end closure arrangement. When the flaps are folded as indicated above and the corners processed as hereinaiiter described, the result is a carton having an end structure as shown in FIG. 3 of the drawing showing a perspective view of a completed carton. In the event the lower end of the blank of FIG. 1 is formed like the upper end, it will be understood that the lower end of the completed carton in FIG. 3 will be substantially a duplicate of the upper end and consequently, the description will refer primarily to the upper end of the carton. It should also be noted that FIGS. 4, 5, 6 and 7 show an enlarged View of one of the corners at the vupper end of the carton for" convenience in more that the end flaps and .12 have irst been folded inv wardly,vand that thereafter, the end flaps 13 and 11 have lbeen folded over the aps 10l and .12 in the `order named and adhesively secured thereto aud to each other, the outer flap'shown thus being `11. Thus the flaps 11, 13 and 10 Aare in overlapping relation directly at the apex of the carton corner.

As the rflaps are folded inwardly, their central portions fold yabout horizontal score lines 32, 3-3, 34, 35 and 36, as

the case may be, While the corner portions fold along score lines `52 orf I53. Thus, lwhen the flaps are folded as described, a triangular corner portion 56a, as shown in FIGS. 4 and 5, will be inclined upward at an angle to the plane of the main portion of the outer end flap 1'1. As lwill be described hereinafter, the triangular portion 56a -may thenY be pfushed downward by suitable means, as a result of 4which the paperboard tends to buckle inwardly in adjoining triangularpanels. This results in buckling of the corner portion of the container in such a manner that allopenings at the corner are closed by the buckled paperboard, and in the event the corner is thereafter subjected to impact, the corner can give without resulting in rupture of the paperboard at the corner. Thus in effect we have a bellows fold action which effectively seals the corner against leakage of the carton contents, and this is true regardless of 'whether the ladhesive between the aps extends tothe apex of the corner.

Referring now to FIG. 8 of the drawings, a mandrel 57 is provided having relieved corner portions 58, together "with a pressure pad 59', and a second pressure pad 60. f During formation of the carton, it is initially placed on the .'mandrel, and the sidewall panels of the carton tube are securely held against the walls of the mandrel by hand or by other suitable means in order to prevent endwise movement of the carton tube on the mandrel. The foldable end aps are then folded over and adhesively secured together as heretofore described, the relieved corner portions 58 allowing for the subsequent buckling inwardly of the corners of the finished carton end as previously described. Following folding of the end flaps, they are pressed togetherA by means of the pressure pad 59, following which the pressure pad 60` is pressed lagainst the end of the carton. The pressure pad '60 is provided with wedge shaped members `61 at each corner, and these are preferably made of a somewhat resilient material such as rubber, although in some instances they may be made of a firm and non-resilient material if desired. When the pressure pad '60* is pressed against the end of the carton, the wedge shaped members 61 serve to press the triangular portions 56a at the corners of the carton downward below the plane of the main portion of the carton end, and when the pressure pad is removed, the paperboard tends to spring backward or upward in such a manner that the end of the carton, as shown in FIG. 6, presents a substantially plane surface, with the diamond shaped portions at the corners being buckled inwardly as heretofore described. As the corners are buckled inwardly, each diamond shaped panel folds in the form of four substantially triangular panels 62, i63, 64 and 165, the panels `62 and 64 folding inwardly in generally overlapping relationship, and the panels 63 and i6'5 folding inwardly in like manner. The triangular panels l64 and 65 are partially hidden in FIG. 6 due to the drawing perspective, but the relationship of the inwardly folded triangular panels is clearly shown in FrIG. 7. The paperboard is thus crowded at the corners of the carton to effectively close the pin holes which would be present if the carton were formed in the conventional manner. The lower triangular panels I62 and 63 are a part of wall panels '5 and 16 respectively, and the upper triangular panels 64 and l65 are a part of the end aps at the ends of wall panels 5 and 6.

'Following this operation, the carton is removedfrom the mandrel, filled with the desired product, after which the end aps at the open end of the carton are folded 60. The carton is now completed, and provides a structure having corners which are sift-proof and of pleasing appearance. The carton side walls are strong enough to allow sealing of the end flaps along their edges, the corners being sealed as described. lIf it is desired to have 'only the bottom end of the cartonsift-proof, it will be L understood that the-other end of the carton may take any other suitable form which may be desired. In addition, the invention is not confined to rectangular cartons, but may be applied to other cartons of polygonal cross section. It should also be pointed out that the provision of the notch '54 in the left-edge of the blank of FIG. l, aswell as the notch 55, facilitates the folding operation at the glue -flap corner since the notches provide for a single thickness of paper board on the triangular portion of the glue ap which is buckled inwardly during depressingl of the triangular corner portions 56a at the end of the carton. If this triangular notch were not provided, a double thickness of paperboard would have to be buckled inwardly at this particular corner of the blank, and due to the stiffness imparted to the structure by the double thickness, it would be difficult orimpossible to press the triangular portion 56a at this particular corner of the corner downward so that the outer surface would lie in the plane of the remaining portion of the carton end.

Although the invention lhas been illustrated and described with considerable particularity, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit of the invention. Reference will therefore be had to the appended claims for a definition ofthe limits of the invention.

What is claimed is:

1. A one-piece blank for a sift-proof carton formed i of sheet material including a plurality of vertical wall panels, each pair of adjacent panels being joined along a `vertical score line, a foldable end flap at the upper end of each wall panel joined to the corresponding wall panel along a horizontal score line, a cut line separating each pair of adjacent end flaps and terminating an appreciable distance above the center line of the horizontal score lines between the Wall panels and end flaps, and score lines on each pair of adjacent wall panels and corresponding end flaps defining a small diamond shaped panel common to the wall panels of said pair and to the corresponding end tiaps, the horizontally opposed apices of the diamond shaped panel being positioned respectively on opposite sides of the center line between the wall panels of said pair and lying at the ends of the horizontal score lines between said wall panels and corresponding end taps, and the vertically opposed apices of said diamond shaped panel being positioned respectively above the center line of said horizontal score lines at the terminus of the cut line between said corresponding end aps and at the end of the vertical score line between said pair of wall panels below the center line of said horizontal score lines.

2. A one-piece blank for a sift-proof carton as set forth in claim 1, wherein the included angles between the score lines at the vertically opposed `apices of the diamond shaped panels are obtuse angles.

3. A one-piece blank for a sift-proof carton of sheet material including a plurality of wall panels, the sides of adjacent panels being dened by vertical score lines, a foldable end flap at the upper end of each wall panel, a horizontal score line at the junction of each wall panel and adjacent end flap, cut lines separating each pair of adjacent end flaps, the cut lines terminating an appreciable distance above the center line of said horizontal score lines, and a substantially diamond shaped panel connect- Ling each pairv of adjacent Wall panels with a corresponding pair of end flaps adjacent to said wall panels and being integral with said -wall panels and end flaps, each diamond shaped panel being dened by a score line on each wall panel of said pair and a score line on each corresponding end flap, the upper apex of each diamond shaped panel being at the lower end of the cut line separating the corresponding end tlaps, the lower yapex being at the end of the vertical score line at the junction of each pair of wall panels and below the center line of said horizontal score lines, and the other two apices of the diamond shaped panel being at the ends of said horizontal score lines on opposite sides of the center line of said vertical score line and substantially equally spaced therefrom.

4. A one-piece blank for a sift-proof carton `of polygonal cross section formed or' sheet material, said blank including Vertical outer side Wall panels on either side thereof and intermediate adjoining wall panels, a vertical glue ap panel adjoining one of said outer side 'wall panels on one rside of the blank, foldable end llaps at least at one end of said Awall panels :and lglue flap panel, aligned horizontal score lines lat the junction of the vertical panels and corresponding end ilaps, vertical score lines at the junction of said vertical panels, diverging score lines on the vertical panels extending from a `common point on each vertical score line to the |horizontal score lines `and intersecting the latter on either side of said vertical score line, said diverging score lines having an `obtuse included angle, converging score lines on said end aps extending from the junctions of said diverging lscore lines with the horizontal score lines and intersecting on the center lines off the corresponding vertical score lines, said converging score lines having an obtuse included angle, and said diverging and converging score line-s `defining a substantially diamond shaped pane, cut lines separating said end liaps, said latter lines being substantially in alignment with the corresponding vertical score lines and terminating substantially at the junctions of the corresponding converging sco-re lines, `and a triangularshaped notch cut in the blank at the edge of said yother outer wall panel and adjacent end flap, the sides of said notch being defined by a pair of cut Ilines extending from .a common point on the score line between said other outer wall panel and adjacent end flap, one cut line terminating Iat the edge of said other outer wall panel and the other cut line terminating at the edge of the said adjacent end flap, said one cut line having the same angle to said'horizontal scorelines as said diverging score lines 'and said other cut line having the same angle to said horizontal score lines as said converging score lines, the lengths of said cut lines being respectively substantially the same las the lengths of said diverging and converging score lines.

5. A Iblank for a sift-proof carton ias set forth in claim 4, wherein the other end of the blank includes said foldable end `iaps, horizontal score lines, diverging and converging score lines, cut lines, and said triangular notch cut in the blank at the edge of said other `outer wall panel and adjacent end ap.

6. A one-piece blank for a lsift proof carton of rectangular cross section formed of sheet material, said blank including four vertical Wal-l panels joined along vertical score lines, a foldable end ap at the end of each wall panel joined thereto along a horizontal score line, the end flaps at the ends of at Ileast two alternate Wall panels having substantially the same length as the width of the other two wall panels, la cut line separating each pair of adjacent end flaps and terminating an appreciable distance above the center line ofthe horizontal score lines between the wall panels and end flaps, :and score lines `on each pair of adjacent wall panels and corresponding end flaps delining a small diamond shaped panel common to the Wall panels of said pair and to the corresponding end tlaps, the horizontally opposed apices of the diamond shaped panel being positioned on opposite lsides of the center line between the wall panels lof s-aid pair fand lying at the ends of the horizontal score lines between said Wall panels and corresponding end aps, and the vertically opposed apices of said diamond shaped panel :being positioned respectively above the center line of said horizontal score lines at the terminus of the cut fline between said corresponding end aps and at the end of the vertical score line between said pair of wall panels below the center line of said horizon-tal score lines.

Guyer etal Nov. 26, 1946 Brooks May 14, 1957 

1. A ONE-PIECE BLANK FOR A SIFT-PROOF CARTON FORMED OF SHEET MATERIAL INCLUDING A PLURALITY OF VERTICAL WALL PANELS, EACH PAIR OF ADJACENT PANELS BEING JOINED ALONG A VERTICAL SCORE LINE, A FOLDABLE END FLAP AT THE UPPER END OF EACH WALL PANEL JOINED TO THE CORRESPONDING WALL PANEL ALONG A HORIZONTAL SCORE LINE, A CUT LINE SEPARATING EACH PAIR OF ADJACENT END FLAPS AND TERMINATING AN APPRECIABLE DISTANCE ABOVE THE CENTER LINE OF THE HORIZONTAL SCORE LINES BETWEEN THE WALL PANELS AND END FLAPS, AND SCORE LINES ON EACH PAIR OF ADJACENT WALL PANELS AND CORRESPONDING END FLAPS DEFINING A SMALL DIAMOND SHAPED PANEL COMMON TO THE WALL PANELS OF SAID PAIR AND TO THE CORRESPONDING END FLAPS, THE HORIZONTALLY OPPOSED APICES OF THE DIAMOND SHAPED PANEL BEING PISITIONED RESPECTIVELY ON OPPOSITE SIDES OF THE CENTER LINE BETWEEN THE WALL PANELS OF SAID PAIR AND LYING AT THE ENDS OF HORIZONTL SCORE LINES 